The present invention relates to cartridged ammunition for machine weapons, particularly for automatic weapons. The ammunition includes a combustible casing, containing the propelling charge composed of loose granular matter, and a projectile fastened to the front of the casing.
Developments in the ammunitions art in connection with cartridged ammunition range from ammunition having a metal casing, which requires the unloading of the casing after firing, to caseless ammunition in which, after firing, the next cartridge can be loaded into the weapon without requiring any unloading process. For large-caliber ammunition, for example, 120 mm, the conventional metal casing is replaced by a casing which, in the cylindrical casing portion, is made of a combustible material. For reasons of obturation and defined ignition, such a casing still includes a metal base. For smaller caliber ammunition, in a range from about 20 to 40 mm, various solutions have been proposed to provide completely non-metallic casings. One such solution is to connect the projectile directly to a compressed, shape-stable propelling charge packet, where the propelling charge is composed of propelling charge granules held together by an adhesive. Other solutions include providing individually compressed rods held together by an adhesive, or a wound propelling charge body.
One of the greatest disadvantages of using such ammunition for automatic weapons firing at high cadences of, for example, 600 rounds per minute, is the intake shock, in addition to the obturation when fired.
The term "intake shock" is here understood to mean all stresses, such as impact, bending, tensile or pressure stresses, which act on the cartridge due to the high acceleration and deceleration of the cartridge when traveling from the magazine to the cartridge chamber of the weapon during the loading process or in the reverse direction during the ejecting process. Thus, during loading, these stresses frequently cause individual powder granules or edges to break off, or cause the bonded propelling charge body to break apart with a simultaneous loosening of the firm connection between the projectile and the charge body. A particular problem is encountered in making a breakage-resistant connection between the tail of the projectile and the propelling charge body, since the heavy projectile tends to break away from the propelling charge due to the inertia of the projectile or the motion energy still inherent in the projectile when the propelling charge body is stopped abruptly in the charge chamber or cartridge chamber of the weapon.
Ammunition of the above-mentioned type is disclosed in U.S. Pat. No. 3,658,008. It is composed of a projectile and a cylindrial, combustible casing of the same caliber which is made uniformly of one piece which comprises a shaped propelling agent granulate and a nitrocellulose binder, containing a small amount of nitrogen, for holding the propelling agent together. A multi-part screw connection is provided to fasten the projectile to the propelling charge casing. One end of the casing is provided with a conically contracted edge or flange, and a conically widened neck piece having external threads is inserted into the casing. A connecting ring having a bore with an internal thread is screwed onto this neck piece in such a manner that the conically constricted casing flange is clamped between the widened neck piece and the connecting ring, both of which may be made of steel or brass. The projectile is provided with an externally threaded shank screwed into the other side of the connecting ring. Because the neck piece has a larger diameter than the opening in the conical flange of the casing, the neck piece must be ground at two opposing sides and the opening in the conical flange must have two opposing recesses to enlarge its diameter to allow the neck piece to be inserted into the opening of the conical flange.
The drawbacks of this prior art ammunition are the labor-intensive and cost-intensive manufacture of all these individual parts. Complicated process steps are required to provide the projectile and the additional members with their complementary threads and opposing conical clamping faces. Therefore, the manufacture of this combustible cartridge casing as a one-piece unit having the conical flange presents production engineering difficulties.